Neurotransmitter transporters are located in the membranes of nerve terminals and other parts of neurons and function to remove extracellular neurotransmitter from extracellular spaces. Inhibition of transporters causes a variety of dramatic behavioral and neurochemical effects. A number of important therapeutic and abused drugs utilize transporters as their targets or "receptors." For example, ritalin, antidepressant drugs, and psychostimulant drugs all inhibit various neurotransmitter transporters. The goal of this project is to study the factors that control the synthesis and degradation of transporter proteins. These factors ultimately control the presence and levels of transporter proteins. The project at this stage involves the use of rodents, and at later stages will involve nonhuman primate species.